Dataset Information

Elevated CO2 alleviates the negative impact of heat stress on wheat physiology but not on grain yield.

ABSTRACT: Hot days are becoming hotter and more frequent, threatening wheat yields worldwide. Developing wheat varieties ready for future climates calls for improved understanding of how elevated CO2 (eCO2) and heat stress (HS) interactively impact wheat yields. We grew a modern, high-yielding wheat cultivar (Scout) at ambient CO2 (aCO2, 419 ?l l -1) or eCO2 (654 ?l l-1) in a glasshouse maintained at 22/15 °C (day/night). Half of the plants were exposed to HS (40/24 °C) for 5 d at anthesis. In non-HS plants, eCO2 enhanced (+36%) CO2 assimilation rates (Asat) measured at growth CO2 despite down-regulation of photosynthetic capacity. HS reduced Asat (-42%) in aCO2- but not in eCO2-grown plants because eCO2 protected photosynthesis by increasing ribulose bisphosphate regeneration capacity and reducing photochemical damage under HS. eCO2 stimulated biomass (+35%) of all plants and grain yield (+30%) of non-HS plants only. Plant biomass initially decreased following HS but recovered at maturity due to late tillering. HS equally reduced grain yield (-40%) in aCO2- and eCO2-grown plants due to grain abortion and reduced grain filling. While eCO2 mitigated the negative impacts of HS at anthesis on wheat photosynthesis and biomass, grain yield was reduced by HS in both CO2 treatments.

SUBMITTER: Chavan SG

PROVIDER: S-EPMC6859723 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Elevated CO2 alleviates the negative impact of heat stress on wheat physiology but not on grain yield.

Chavan Sachin G SG Duursma Remko A RA Tausz Michael M Ghannoum Oula O

Journal of experimental botany 20191101 21

Hot days are becoming hotter and more frequent, threatening wheat yields worldwide. Developing wheat varieties ready for future climates calls for improved understanding of how elevated CO2 (eCO2) and heat stress (HS) interactively impact wheat yields. We grew a modern, high-yielding wheat cultivar (Scout) at ambient CO2 (aCO2, 419 μl l -1) or eCO2 (654 μl l-1) in a glasshouse maintained at 22/15 °C (day/night). Half of the plants were exposed to HS (40/24 °C) for 5 d at anthesis. In non-HS plan ...[more]

PMID: 31504692

Similar Datasets

Project description:The current perspective of increasing global temperature makes heat stress as a major threat to wheat production worldwide. In order to identify quantitative trait loci (QTLs) associated with heat tolerance, 251 recombinant inbred lines (RILs) derived from a cross between HD2808 (heat tolerant) and HUW510 (heat susceptible) were evaluated under timely sown (normal) and late sown (heat stress) conditions for two consecutive crop seasons; 2013-14 and 2014-15. Grain yield (GY) and its components namely, grain weight/spike (GWS), grain number/spike (GNS), thousand grain weight (TGW), grain filling rate (GFR) and grain filling duration (GFD) were recorded for both conditions and years. The data collected for both timely and late sown conditions and heat susceptibility index (HSI) of these traits were used as phenotypic data for QTL identification. The frequency distribution of HSI for all the studied traits was continuous during both the years and also included transgressive segregants. Composite interval mapping identified total 24 QTLs viz., 9 (timely sown traits), 6 (late sown traits) and 9 (HSI of traits) mapped on linkage groups 2A, 2B, and 6D during both the crop seasons 2013-14 and 2014-15. The QTLs were detected for GWS (6), GNS (6), GFR (4), TGW (3), GY (3) and GFD (2). The LOD score of identified QTLs varied from 3.03 (Qtgns.iiwbr-6D) to 21.01 (Qhsitgw.iiwbr-2A) during 2014-15, explaining 11.2 and 30.6% phenotypic variance, respectively. Maximum no of QTLs were detected in chromosome 2A followed by 6D and 2B. All the QTL detected under late sown and HSI traits were identified on chromosome 2A except for QTLs associated with GFD. Fifteen out of 17 QTL detected on chromosome 2A were clustered within the marker interval between gwm448 and wmc296 and showed tight linkage with gwm122 and these were localized in 49-52 cM region of Somers consensus map of chromosome 2A i.e. within 18-59.56 cM region of chromosome 2A where no QTL related to heat stress were reported earlier. Besides, three consistent QTLs, Qgws.iiwbr-2A, Qgns.iiwbr-2A and Qgns.iiwbr-2A were also detected in all the environments in this region. The nearest QTL detected in earlier studies, QFv/Fm.cgb-2A was approximately 6cM below the presently identified QTLs region, respectively Additionally, QTLs for physiological and phenological traits and plant height under late sown and HSI of these traits were also detected on chromosome 2A. QTL for HSI of plant height and physiological maturity were located in the same genomic region of chromosome 2Awhereas QTLs for physiological and phonological traits under late sown were located 8cM and 33.5 cM below the genomic location associated with grain traits, respectively in consensus map of Somers. This QTL hot-spot region with consistent QTLs could be used to improve heat tolerance after validation.

Project description:Heat and drought events often occur concurrently as a consequence of climate change and have a severe impact on crop growth and yield. Besides, the accumulative increase in the atmospheric CO2 level is expected to be doubled by the end of this century. It is essential to understand the consequences of climate change combined with the CO2 levels on relevant crops such as wheat. This study evaluated the physiology and metabolite changes and grain yield in heat-sensitive (SF29) and heat-tolerant (LM20) wheat genotypes under individual heat stress or combined with drought applied during anthesis at ambient (aCO2) and elevated CO2 (eCO2) levels. Both genotypes enhanced similarly the WUE under combined stresses at eCO2. However, this increase was due to different stress responses, whereas eCO2 improved the tolerance in heat-sensitive SF29 by enhancing the gas exchange parameters, and the accumulation of compatible solutes included glucose, fructose, β-alanine, and GABA to keep water balance; the heat-tolerant LM20 improved the accumulation of phosphate and sulfate and reduced the lysine metabolism and other metabolites including N-acetylornithine. These changes did not help the plants to improve the final yield under combined stresses at eCO2. Under non-stress conditions, eCO2 improved the yield of both genotypes. However, the response differed among genotypes, most probably as a consequence of the eCO2-induced changes in glucose and fructose at anthesis. Whereas the less-productive genotype LM20 reduced the glucose and fructose and increased the grain dimension as the effect of the eCO2 application, the most productive genotype SF29 increased the two carbohydrate contents and ended with higher weight in the spikes. Altogether, these findings showed that the eCO2 improves the tolerance to combined heat and drought stress but not the yield in spring wheat under stress conditions through different mechanisms. However, under non-stress conditions, it could improve mainly the yield to the less-productive genotypes. Altogether, the results demonstrated that more studies focused on the combination of abiotic stress are needed to understand better the spring wheat responses that help the identification of genotypes more resilient and productive under these conditions for future climate conditions.

Dataset Information

Elevated CO2 alleviates the negative impact of heat stress on wheat physiology but not on grain yield.

Publications

Elevated CO2 alleviates the negative impact of heat stress on wheat physiology but not on grain yield.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets